Apparatus for distant hydraulic control



Oct. 27, 1931. A. HUGUENIN APPARATUS FOR DISTANT HYDRAULIC CONTROL Filed June 5, 1929 III/III II A W Q Q a U m C N a m k x .w .1 1 b E a r .l W O Iv h X n\ r 'E l A m,

Patented Oct. 27, 1931 PATENT OFFICE A LBERT HUG-UZENIN, F PARIS, FRANCE AIPPABATUE FOR DISTAN '1' HYDRAULIC CONTROL Application filed June 5, 1929, Serial No. 868,723, and in France October 18, 1928.

In the modern industrial plants which are constantly on the increase, and are also becoming more complicated, a great need is felt for a central control of all the elements or devices serving to determine the operation of the general installation. Such central control is now carried out by mechanical, electric and hydraulic means, and also by compressed air, but the control becomes difiicult to realize when the controlled devices must given position 5 consisting in the fact that the circuit must be frequently broken during all the difi'erent movements, thus causing sparking and also a great wear of the parts, and due to such wear, the controls lose their accuracy, and hence will after a time be put entirely out of use. I

The present invention relates to an exclusively hydraulic method which is most accurate and aflfords the control of the difi'erent actuated devices at all distances and positions with reference to the central controlling apparatus, while at the same time the actuated devices are held fast against all motion, but without the plant and apparatus being submitted to such an amount of wear which will afiect the accuracy of the control of the proper working of the plant for an indefinite length of time. For this purpose, in fact, a liquid under pressure proves a most effective power transmitting agent and can be used by reason of its incompressibility as the substance by which the several actuated devices are held against motion, whatever be the form of construction in use.

The said plants comprise a great number of different controls, according to modern practice in manufacturing plants. For this reason, the cost of installation of the central controlling apparatus must be reduced to a minimum, and herein the hydraulic system offers the additional advantage of a grouping of the controlled devices in lots, and for instance by lots of ten or twelve units.

The appended drawings show by way of example an embodiment of the invention.

Fig. 1 is a diagrammatic view of the controllingapparatus.

Fig. 2 is a vertical section of a distributer already illustrated in Fig. 1, but in another position.

Figs. 3 and 4 illustrate in vertical section a slide valve already shown in Fig. 1, but in two diflerent ositions.

a is an oil ta oil being preferably em ployed as the liquid, since it is a lubricant and will not attack the metals. The said tank or casing contains the essential parts of the device and its top part 6 forms the controlling table or board; 0 is a geared pump, suitably driven, using preferably an electric motor. It is provided with a suction pipe 03 and a delivery pipe 6. On the suction pipe is mounted a gate valve f controlling the feed of the pump. Since the pump operates constantly and at uniform speed, its feed will also be constant, and this supply is to be furnished with the minimum resistance, and thus circulated directly into the casing a so as to reduce the power used when the controlling parts of the in stallation are inoperative, or otherwise this power would be excessive. The pump thus operates during the period in which no effective control takes place, at a very low pressure, so as to reduce the power to the minimum, but as soon as this source of power is connected to a servo-motor having a certain resistance, the pressure at the feeding end of the pump now instantly rises to the value required to overcome this resistance. It is thus evident that in these conditions almost the whole amount of the oil will be withdrawn by the pump from the bottom of the casing a and will return directly to the latter, while 'a certain part of this oil will only be circulated in the servo-motors when these latter are put under control.

The essential object of the apparatus according to the invention is attained in the following manner.

The feeding or delivery pipe 6 of the pump leads to the distributer g and particularly to its annular conduit h, in which, in the present example the oil circulates according to the signs 69 Oin the clockwise direction when the apparatus is viewedfrom the top. The distributer y is. shown in Figure 1 in the inoperative position, and thus the p ston 2' opens the ports is of a sleeve 1, so that the oil from the pump will be discharged according to the arrows, Figure 1, through the orifices m, and descends irectly into the tank a. I

In fact, the piston 2' is connected by its rod n to a controlling piston 0 which slides in the cylinder 9 fixed to the distributor g and is urged by a spring p against a stop g which is adjustable and is mounted on a cover r.

When no servo-motor is acted upon by a control, the circulation of the oil under pressure takes place from the delivery orifice of the pump through the said annular conduit h and the ports k-m, thence descendin directly to the bottom of the casing a. his throttling of the oil is so small that it has practically no effect upon its temperature.

The controlling device itself consists of a valve chests containing a double piston forming a slide valve 15, also the oil feeding conduits u and connecting conduits 'v-'w lead ing to the servo-motors, which may be of the piston type as, or of the type comprising two gear wheels 3 and it is obvious that one slide valve controls only one servo-motor.

The slide valve as shown in Figure 1 is provided with hand control, actuated by a lever 2 which is mounted on a toothed wheel a. The valve can be moved vertically in either direction by a rack b which is formed on the extended rod of the valve. A locking bolt device (not shown) serves to hold the lever in the vertical position when out of use, and thus holds the valve z in its middle position (Fig. 1) corresponding to a free connection between the space comprised between the two parts of the piston valve, and the intake of the oil under pressure supplied by the pipe u, the pressure herein being the same as the pressure in the annular conduit h of the'distributer g.

The two conduits a) and w leading to the servo-motors are entirely closed oil by the two parts of the piston'valve; the two ports of a small conduit 0 connectthe part below the piston o to the said valve chest. The two ports d-e' of said conduit 0 are also closed by the two portions of the piston when in the middle position (Fig. 1). The operative covering of these two portions of the piston with reference to the two ports 03 and e is however much smaller than that of the conduits 'v'w connecting the valve to the servo-motors.

In this manner, when the slide valve is in the inoperative position it entirely closes the the great majority of the conduits, which are in fact situated between the valves and the servo-motor will not be subjected to pressure in the inoperative position, and pressure will onlyoccur when one of the servomotors is operated.

As concerns this operation, reference is made to Figures 2, 3 and 4. Fig. 2 shows the new position assumed during the operation by the movable part 2' n 0 of the distributer. Figs. 3 and 4 show the two characteristic positions of the movable piston valve 6.

If for instance the said lever z is used to raise the valve t, the first efiect of this motion is shown in Figure 3, and after a very short stroke, the port 03 is opened, so that the oil under pressure from the conduit u will circulate according to the arrow (Fig. 3), thus acting upon the lower face of the distributer piston 0, which now rises, compressing its spring 11. As soon as the piston z commences to cover the ports k, the oil which is driven forward by the pump will have no outlet, and thus the output pressure will at once rise and it rapidly increases, thus increasing the speed of the ascending stroke of the piston 0 until this piston is arrested by the stop f at the end of the cylinder.

As it continues to rise, the double piston t finally attains the position shown in Figure 4, and it will be noted that while leaving the port 03 constantly open and thus maintaining the movable portion of the 'distributer g in its upper position, the oil under pressure supplied by the pump can be discharged through the conduit '0 which thus furnishes oil under pressure to the servo-motor while at the same time the conduit w discharges its oil and also .the oil of the servo-motor (according to the of the type a; or y, are held fast in their 'osiin Figs. 4, 3 and 1, and as soon as the position of Figure 3 is again attained, allmotion of the servo-motor w or y will have ceased, this servo-motor being again held against all motion; in theposition of Figure 1 the port (1' will be again closed, thus cutting off the delivery pressure at the lower portion of the piston o of the distributer 9 whose movable portion will return to the position of Figure 1 by the action of its s ring p; the oil below the piston can escape t rough the conduit g in the direction of the arrow, Figure 2, and this oil returns directly into the tank a. When the movable portion z n o of said distributer begins to uncover the ports k of the sleeve Z, the oil discharged by the ump begins to leave the circular conduit Ii in a direct manner, according to the arrows, Figure 1, and to enter the said tank. This evacuation of the oil will be again complete, and the pressure is a minimum in the pump as soon as the said movable portion z' n 0 of the distributer has returned to the position of Figure 1. v

7 Obviously, the conduit g,'which is permanently in communication with the bottom 1' of the distributer, has a small section, in such manner that when the whole output of the pump circulates through the port 03 (now open) and comes below the piston o, the resulting loss of oil will be negligible and the operations will occur exactly as described.

The operations herein specified take'place when the piston t is raised by the lever a, that is, when the lever is moved (Fig. 1) to the right and is returned to the middle position, and in this case the conduit '22 becomes the supply conduit and the conduit to serves for the discharge. However, if the lever is moved to the left (Fig. 1) and then returned to the middle position, the same operation will take place, but herein the port 6' connects the feed of the pump to the portion below the piston 0 of the distributer, and the conduit 'w becomes the supply conduit and the conduit 1) serves for the discharge, this discharge of oil takes place directly into the tank a through the apertures h in the direction of the arrow (Fig. 1). All other factors being equal, what will take place is the inverse motion of the controlling element or device operated by the servo-motor of the type a: or y.

Obviously, one distributer is provided for a whole series of slide valves, and this number is limited in practice only by the degree of fluid tightness of the double pistons t. In Fig. 1, a single slide valve can be seen, because the other slide valves are similar and exactly located behind the first one. The same conduit u supplies all these slide valves through a transverse header u, and all the slide valves feed the same cylinder 9 through a transverse header 0 The plant according to the invention is thus distinguished by the use of a very limited number of parts, and is therefore of an inexpensive nature.

Should in any case the control of a servomotor be carried out to an excessive degree, so that for either direction of movement of the servo-motor the piston 23 is held in the 2" which is connected directly'by the pipe 70 to the annular conduit h, and the operating pressure on the valve is adjustable, since its spring 1' is adjustable by the nut m. The oil from said valve flows through the orifice n and thus returns directly to the tank a.

The arrangement herein represented is given solely by way of example, and the same principle may be embodied in other forms of construction.

Claims:

1.- In a distant hydraulic control, the combination of a vessel for a liquid, a pump for sucking and delivering the said liquid, a servo-motor adapted to be actuated in either direction by the liquid delivered by the said pump, a slide valve actuated by hand and serving to control the admission and escape of the liquid delivered by the pump, respectively to both sides of the servo-motor a distributer causing the delivery conduit of the pump to alternatively communicate with the said vessel and with the slide valve, and control means for actuating the said distributer, these means being actuated in one direction by a spring, and, 1n the opposite direction, by the liquid delivered by the pump, the said slide valve being adapted to admit the liquid delivered by the pump into the said control means a short time before admitting it into the servo-motor, substantially as illustrated and described and for the purpose set forth.

2. In a distant hydraulic control, the combination of a vessel for a liquid, a pump adapted to suck the liquid in this vessel, a distributer comprising a chamber receiving the liquid delivered by the pump and having outlet openings for allowing the said liquid to return within the said vessel, a movable obturating member adapted to close the said openings, a cylinder, a piston sliding in said cylinder and adapted to move the said obturating member and a spring pushing said piston, a servo-motor, a distributing cylinder, a slide-valve in said distributing cylinder, this cylinder having orifices respectively connected, on the one hand to the said chamber receiving the liquid delivered, on the other hand, to the said cylinder having the spring actuated piston, on the other hand to the liquid vessel, and finally to the said servomotor, this slide valve being adapted to be actuated by hand and to control the said orifices, the latter being so arranged that, in its position of rest, 1 he said slide valve obturates the communications of the said distributing cylinder with the said spring actuated piston and with the said servo-motor that in one of its working positions it allows the said chamber receiving the liquid delivered to commuj liioate the seiiicjlinder sctuated'piston-,"andjthet inamore advanced; workin position, it-allows, on the onehand w the san chamber to communicate with one of the sides of the servo-motor and, on the other hand, the other side of the servo-motor I to communicate-with the said exhaust orifices connected to the liquid vessel. 7

In testimony whereof I have hereunto affixed my signature.

/ ALBERT HUGUENIN. 

